XXV111 CONTENTS 



Chapter XXIX 



INFLUENCE OF ENVIRONMENTAL CONDITIONS, SOIL TREATMENT, AND PLANT GROWTH 

 UPON MICROORGANISMS AND THEIR ACTIVITIES IN THE SOIL 



Influence of organic matter upon the soil population. Influence of stable 

 manure. Influence of temperature. Influence of moisture. Influence of 

 soil cultivation. Influence of salt concentration upon the activities of 

 microorganisms in the soil. Influence of calcium oxide and carbonates of 

 calcium and magnesium. Influence of growing plants upon soil micro- 

 organisms and their activities 767 



Chapter XXX 



SOIL AS A HABITAT FOR MICROORGANISMS CAUSING PLANT AND ANIMAL DISEASES 



Influence of saprophytic soil microorganisms upon plant growth. Sapro- 

 phytism and parasitism among soil microorganisms. Animal and plant 

 diseases caused by bacteria that may be found in the soil. Plant diseases 

 caused by fungi found in the soil. Plant and animal diseases caused by 

 species of actinomyces. Plant and animal diseases caused by invertebrate 

 animals found in the soil. Relation of soil environment to plant infection. 

 Influence of reaction upon the growth of plant pathogenic organisms in the 

 soil. Methods of control SOI 



Chapter XXXI 



SOIL INOCULATION 



Beneficial and injurious microbiological processes in the soil. Introduction 

 of certain useful microorganisms into the soil. Legume inoculation. Use 

 of soil for inoculation of legumes. Commercial cultures and their prepara- 

 tion. Biological types of legume bacteria. Importance of legume inocula- 

 tion. Inoculation of non-leguminous plants with nodule bacteria. Inocu- 

 lation of soil with non-symbiotic nitrogen-fixing bacteria. Soil inoculation 

 with autotrophic bacteria. Inoculation of soil with heterotrophic, non- 

 nitrogen-fixing microorganisms 817 



Chapter XXXII 



HISTORY OF SOIL MICROBIOLOGY, ITS PAST, PRESENT AND FUTURE 



Beginnings of soil microbiology. Soil microbiology as an independent 

 science. Recent advances of the science. Present outstanding problems 

 in soil microbiology 834 



